Valve-gear



- 3 Sheets -Sheet 1. E. HILL.

VALVE GEAR.

(No Model.)

Patented Mar. 22, 1887.

3 Sheets-Sheet 2;

(No Model.)

E. vHILL. VALVE GEAR.

Patented 11211222, 1887.

3 SheetsSheet 3. E. HILL.

VALVE GEAR.

(No ModeL) No. 359,865. Patented Mar. 22, 1887.

UNITED STATES PATENT OEEicE.

EBENEZER HILL, OF SOUTH NORW'ALK, CONNECTICUT.-

VALVE-GEAR.

SPECIFICATION forming part of Letters Patent No. 359,865, dated March 22, 1887.

. Application filed Septcmhcr m, 1886. Serial No, 214,611. (No model.)

To all whom it may concern.-

Be it known that I, EBENEZER HILL, of South Norwalk, in the county of Fairfield and State of Connecticut, have invented a. new Improvement in ValveGears; and I do hereby declare the following, when taken in connection with accompanying drawings and the letters of referencemarked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent; in- V Figure 1, aside view of an air-compressor, showing the valve-gearin a position just after the driving-crank has passed its dead-center in one direction; Fig. 2, the same view representing the position of the parts as having justpassed the opposite centerthat is, in a position diametrically opposite the position indicated in Fig. 1; Fig. 3, a diagram illustrating the path of the eccentric-rod at the points where the links are connected thereto; Figs. 4 and 5, modifications in the arrangement of the reciprocating pivot upon which the eccentric-rod is hung; Fig. 6, a modification showing the method as applied to a single valve.

This invention relates to an improvement in the method of and mechanism for operating the induction and eduction valvesof cylinders within which a piston is driven from end to end, and in which an induction and an eduction valve are arranged at one end of the cylinder and like induction and eduction valves for the opposite end of the cylinder, and in which the valves receive a positive movement, the valve-gear being particularly applicable to air-compressors, but maybe employed as a valve-gear for steamengines.

The object of the invention is to operate both the induction and the eduction valves by a single eccentric, and to increase the throw of the valves at those portions of their travel where the ports are opened, and at the same time accelerate the closing movement of the eduction-valves; and it consists in changing the time of a valves movement at different parts of its stroke by changing the direction of its connection with the eccentric-rod.

In illustrating my invention I show it as applied to a compound air-compressor, A be ing the initial cylinder, and B the compress ing-cylindcr; O, the fly-wheel, which is mounted in the usual bcarings,'and which is driven from the prime motor. Upon the shaft of the fly-wheel a crank, D, is fixed, by which the rotary movement of the fly-wheel shaft is communicated to the piston-rod B through the usual connectingrods; but the arrangement of the cylinders, fiy-wheel, and connections constitute no part of my invention. The direction of revolution of the iiywhcel is indicated by an arrow.

The valves of the cylinder A are common rotary or oscillating valves, whose ports open to the respective ends of the cylinderan arrangement of valves too well known to require particular illustration or description, further than to say that a represents the spindle of theinduction-valve at one end of the cylinder and b the spindle of the inductionvalve at the opposite end of the cylinder.

(Z represents the spindle of the eduction valve at the same end of the cylinder as the induction-valve of a, and e the spindle of the eduction-valve at the opposite end of the cylinder, these spindles extending from the valves through the usual stufiing-box, and so that by the rotative movement of the spindle the valves oscillate upon their respective seats to open and close their respective ports, the axis of the several valves being parallel with the axis of the driving-shaft.

On the outer end of the induction-valve spindle aa crank, f, is fixed, and on the other induction-valve spindle, b, a similar crank, g, isfixed. On the eduction-valve spindle d a like crank, h, is fixed, and on the other eduction-va-lvc spindle, e, is a corresponding crank, 2 through which cranks the oscillatory movement is imparted to the respective valves.

To obtain the best results in a machine of this character the inductionwalves must open soon after the dead-center is passcd-that is, at the beginning of the stroke of the piston and should remain open until the stroke is completed. This movement, it is well known, is obtained from an eccentric set at right angles to the crank. The eductionwalve, however, should not be opened until after the piston has moved sufficiently far .toward the eductionport to compress the air to an extent equal to the reservoir-pressure. At that time the ed uction-valve should open and remain open until the stroke is complete, and then should instantly close.

F represents the eccentric, which, as here shown, is in the form of a crank fixed to the pin of the crank D, this being a well-known substitutefor the disk-eccentric, and is employed in this case as a convenience for illustration. From the eccentric F the eccentric-rod G extends longitudinally, and is hung upon a rocking arm, H, at a point midway between the valve-spindles at the respective ends of the cylinders. This arm is hung at I below the cylinder, and extends vertically upward, and is hinged to the eccentric-rod G at J, and so that as the reciprocating movement is imparted to the rod by the eccentric in the usual manner the arm H will swing, say as from the position in Fig.1 to that seen in Fig. 2, and return. The driven end of the eccentric'rod G travels in and makes a complete circle at each revolution of the driving-shaft.

At the point J, or connection between the rocking arm Hand the eccentric-rod G, the

rod travels in a slightly-curved line, but to all practical purposes substantially a straight line, and may be astraight line, if desired. At other points in the rod both sides of the point J the path traveled by such points is elliptt cal; but the direction of travel in such elliptical paths is that on the side of the point J nearest the eccentric, inthe same directionas the eccentric; but on the opposite side of the point J the path is in the opposite direction and as indicated in Fig. 3, and in which the circle at theright indicates the path of the eccentric at the opposite end. Theintermediate series of points 1, 2, 3, 4, 5, 6, 7, and 8 indicatethe position of the pivots at corresponding points in the path of the eccentric. on the side of the said intermediate point next the eccentric the figures 1, 2, 3, 4, 5, 6, 7, and 8 indicate corresponding points in the path of the eccentric-rod at the connection of the valve on that side, and at the extreme left 1, 2, 3, 4,

5, 6, 7, "and 8 indicate corresponding pointsin the movement of the eccentric-rod at the point of connection with the other valve, these three series of points representing equal divisions inthe movement of the eccentric.

From the rod G a link, Z, extends downward, and is connected co the crank g, so that when in the position seen in Fig. 1 the crank stands nearly parallel to the connecting-rod, while the link I is at substantially right angles to the rod. Upon the opposite side of the arm alink, m, connects that end of the eccentric-rod Gwith the crankf on the valve-spindle a, and so that in the position seen in Fig. lthe crank fextends up nearly at right angles to the rod G, and the link at nearlyparallel with therod;

hence when in theposition seen in Fig. 1 the crank f receives the direct longitudinal movement of the rod G, but is not affected to any material extent by the up-and-down movement of the rod, whereas at the same time the crank g partakes of the up'and-down movement of the rod G and not materially of its 1ongitudinal movement.

. The time of the up-and-down movement will be ninety degrees behind the horizontal movement, and will. correspond with the move-. ments of an eccentric set in unison with the movement of the main crank.

From the valve-spindle la, and diametrically opposite the crank f, is a crank, it, from which a connection, 0, is made to the crankh of thei eduction-spindle d and valve-spindle b, and 5 diametrically oppositethe crank g is a crank,

19, from which a connection, 1', is made to the eductionscrank '5. These connections 0 'r are here shown of crescent shape as a matter :of convenience; but their effect is practically the 8G same as if they were straight.

In the position seen in Fig. 1, and as the parts are there indioatedas moving, the inductionvalve of the spindle a is open to admit air into the cylinder. Upon the opposite endi ot' 3 thecylinder the eduction-valve upon the spin-i dlee is open to allow the compressed air :to escape. At this time the induction-'valveof the spindle b is closed, and, because the link Z is at substantiallyright angles to the move ment. of the eccentric-rod G, that valve is not materially affected by the horizontal movement of the eccentric-rod while the eductionvalve of the spindle a is moving under the 1011- gitudinal or horizontal movement of the connecting-rod; but as the rod moves forward under the action of the eccentric-say to the position. seen in Fig. 2thelink-connections gradually change their relativepositionsun til, as seenin Fig. 2,the link m has attained IO) and passed its position at right angles to the pathiof the eccentrierod, while. the link I has reached and is working in a path .parallel with the eccentric-rod. The piston having. now passed the opposite center, the spindle b has been quickly turnediduring this last part of the advance .movement of the eccentric-rod, and while the link Z is moving in a path substantiallyparallel with the path of theirod, and the valve therefore correspondingly quickly opened, whereas at the same time the op posite induction-valve of spindle a has been closed, and its link m, coming into the yerticalposition, or position at right angles to the path of the eccentricrod;attains but slight n5 movement from the eccentric rod, and the same which the valve-spindle b on the other induction-valve attained when the valve of the spindle a was opening.

The cranks a andp on the induction-valve spindles being diametrically opposite thev cranks f g of the said spindles, and throughi which they are operated, it follows that when the said eduction-valvecranks are receiving the movement under the longitudinal or horizontal movement of the eccentric-rod the cranks n p are respectively passing their dead-center with relation to the exhaustvalves, andihence in such position very little movement is imparted to the e'xhaust-valvesthat is to say,

IIO

in Fig. 1, while the induction-valve is being rapidly moved, the crank n is imparting very little movement to the exhaust-valve spindle d at that end of the cylinder, whereas at the opposite end of the cylinder the up-and-down movement of the eccentric-rod is imparting very little movement to the valve-spindle b; but that movement is communicated to the exhaustcrank i, and the exhaust-valve is therefore at this time receiving its quickest move ment; but arriving at the opposite points, as in Fig. 2, this condition, it will be observed, is reversed. Thus practically the inductionvalves are operated under the longitudinal movement of the eccentric-rod, while the eduction-valves are operated by the up and-down movement of the eccentric-rods;

It will be observed that in the illustration the throw of the eccentric is twice as great as the length of the cranks f 9; but because of the swinging movement of the respective links Z m, whereby they change their direction after the inductionporls are closed and while the same ports are being opened, the short cranks are permissible, and consequently a correspondingly quick movement under the greater throw of the eccentric, and because of the connection with the exhaust-valves, as described, a correspondingly quick closing and opening of the exhaust-valves is produced, and so quick as to be practically instantaneons, and the movement of all the valves is produced by a single eccentric.

I have stated that this valve-gear is applicable to a steam-engine as well as to an aircompressor, for mechanically an air compressor is simply a steam-engine driven in a direction opposite to that for which the valves are properly set for the admission and escape of steam.

While I prefer to employ the rod H as a means for supporting the pivot upon which the eccentric-rod is h ung,so that that pivot may partake of the reciprocating movement of the rod, the pivot may be arranged upon a slide, which will reciprocate in a perfectly-straight path-say as seen in Fig. 4--or the rod may slide through a pivoted box. as seen in Fig. 5.

The method of changing the time of the induction valves may be performed without necessarily connecting the same to the eduction-valves-that is to say, the education-val ves may be operated in any of the \vellknown methods of operating the eduction-valves in dependent of the mechanism for operating the induction-and the method of so changing the movement .of a valve may be applied to a single valve, as indicated in ig. 6. I there fore do not wish to be understood as limiting the invention to the combination of connections from the single eccentric-rod to all the valves; but by this method I am thus enabled to operate all the valves by a single rod.

I claim- 1. The method herein described for chang ing the time of a valves movement at different parts of its stroke, and which consists in automatically changing the direction of the valves connection with the eccentric'rod during the movement of the valve, substantially as described. I

2. The herein-described valvegear for operating oscillating induct-ion and eduction valves, consisting in the combination of an eccentric, an eccentric-rod extending therefrom and hung upon a pivot in a position between the valve-spindle at one end of the cylinder and the valve-spindle at the opposite end of the cylinder, and whereby under the longitudinal reciprocating movement imparted to the rod by the eccentric an up-anddown movement is imparted to the said eccentric- :rod by said pivot, a crank on each of the valve-spindles, a link connecting one valve crank with the rod upon one side of its said pi'vot,'and a similar link connecting the other crank with the said rod upon the opposite side of said pivot, substantially as described.

3. The herein-described valve-gear for the operation of induction and eduction valves, consisting of an oscillating induction and an oscillating eduction valve, whose ports open into one end of the cylinder, and alike induction and an ed action valve, whose ports open to the opposite end of the cylinder, the axis of said valves being substantially parallel with each other, an eccentric, an eccentricrod extending therefrom and hung upon a pivot in a position between the valve-spindlesat one end of the cylinder and the valve-spindles at the opposite end of the cylinder, and whereby under the longitudinal reciprocating movement imparted to said eccentric-rod it will also receive an up-and-down movement, a crank on each of the said valve spindles, a link connecting one of the valve-cranks at one end with the rod upon one side of its said pivot, and a similar link connecting a valvecrank at the opposite end of the cylinder with the said rod upon the opposite side of said pivot, and a connection between the two cranks so connected to the eccentric-rod and the cranks of the other valves at the respective ends of the cylinder, substantially as described.

EBENEZER HILL.

Vitnesses:

G. J. HILL, HENRY H. J ENNINGS. 

